Asymmetrical pressure relief vent

ABSTRACT

One or more valves may be employed in a pressure relief vent of a vehicle. The valves may have asymmetrical closing characteristics of differing pressuring inducing closing characteristics or both in order to reduce the peak noise generated as the valves are closing.

BACKGROUND OF THE INVENTION

The present application relates generally to a pressure relief ventassembly for use in relieving air pressure in a vehicle.

Modern automotive vehicles typically include pressure relief vents,mounted somewhere on the body of the vehicle, to selectively allow forair flow out of the passenger compartment of the vehicle while limitingairflow in the opposite direction. The air flow occurs when the airpressure in the vehicle is greater than the atmospheric pressure outsidethe vehicle by a predetermined amount. For example, the pressure insidethe vehicle may rise temporarily when a vehicle door is closed. Thepressure relief vents open during these events, thus avoiding airpressure levels that would be uncomfortable for the vehicle occupants.

The typical body pressure relief vents used on automotive vehicles haveuniform and symmetrical flaps and hinges, so they generally open andclose simultaneously for given pressure differentials between thevehicle passenger compartment and atmospheric pressure. While adequatelyrelieving the pressure, an issue that sometimes arises with these ventsis that the noise generated when all of the flaps slap shut (i.e.,impact against a frame of a valve housing) at the same time irritatessome vehicle occupants. This may occur, for example, during the vehicledoor closing event. The combined noise from all of the flaps may be moreeasily heard in certain types of vehicles, such as pickup trucks wherethe pressure relief valve may be located on the back of the cab,allowing this undesirable slapping noise to be more easily heard by theoccupants.

Since there are some occupants who find this noise objectionable,solutions have been proposed that attempt to solve this concern. Forexample, hot glue dollops have been applied to each flap along itshinge. But this limits the flow rate of air out through the valves morethan is desirable and adds more cost to the pressure relief valveassembly than is desired. In another example, nibs have been added toeach flap or the frame around the flaps where the two contact. But thisallows an increase in backflow through the valves that may be higherthan is desirable. Thus, a cost effective way to reduce or eliminatethis noise, while still allowing for the body pressure relief functionto be performed adequately, is desired.

SUMMARY OF THE INVENTION

An embodiment contemplates a valve for use in a pressure relief ventassembly for a vehicle. The valve may include a valve housing having aframe defining a vent opening; and a flap having a periphery extendingaround and covering the vent opening, with the periphery including ahinge edge affixed to the frame. The flap includes a hinge adjacent tothe hinge edge that is bendable when a pressure in the vehicle isgreater than a pressure outside of the vehicle, and an asymmetricclosing characteristic, wherein the asymmetric closing characteristicinduces a twisting in the flap when the flap opens and closes.

An embodiment contemplates a pressure relief vent assembly for avehicle. The pressure relief vent assembly may include a valve housinghaving a frame defining a first vent opening and a second vent opening.A first flap has a first periphery extending around and covering thefirst vent opening, with the first periphery including a first hingeedge affixed to the frame, the first flap including a first hingeadjacent to the first hinge edge that is bendable when a pressuredifferential is greater than a first pressure difference between apressure in the vehicle and a pressure outside of the vehicle defining afirst pressure inducing closing characteristic. A second flap has asecond periphery extending around and covering the second vent opening,with the second periphery including a second hinge edge affixed to theframe, the second flap including a second hinge adjacent to the secondhinge edge that is bendable when the pressure differential is greaterthan a second pressure difference between the pressure in the vehicleand the pressure outside of the vehicle defining a second pressureinducing closing characteristic, with the second pressure inducingclosing characteristic being different than the first pressure inducingclosing characteristic.

An embodiment contemplates a method for relieving a pressure from insideof a vehicle through a pressure relief vent assembly, the methodcomprising the steps of: providing a valve, having a frame defining avent opening covered by a flap having a hinge, to selectively allow fora flow of air from the inside of the vehicle to outside of the vehiclethrough the vent opening; bending the flap about the hinge to open thevent when the pressure inside the vehicle is greater than a pressureoutside of the vehicle by a predetermined amount; and inducing atwisting in the flap as the flap is bent about the hinge such that aperiphery of the flap will contact the frame around the vent openingsequentially upon closing.

An advantage of an embodiment is a reduction in the peak noise levelcreated by the flaps when the valves are closing. This is accomplishedwith minimal cost, without limiting the air flow through the valves toan undesirably low level, and without increasing the backflow of airthrough the valves to an undesirable level.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pressure relief vent assemblyaccording to a first embodiment.

FIG. 2 is a front view of the assembly of FIG. 1.

FIG. 3 is a view similar to FIG. 2, but illustrating a secondembodiment.

FIG. 4 is a front view of a portion of a pressure relief vent assemblyaccording to a third embodiment.

FIG. 5 is a view similar to FIG. 4, but illustrating a fourthembodiment.

FIG. 6 is a view similar to FIG. 4, but illustrating a fifth embodiment.

FIG. 7 is a view similar to FIG. 4, but illustrating a sixth embodiment.

FIG. 8 is a view similar to FIG. 4, but illustrating a seventhembodiment.

FIG. 9 is a view similar to FIG. 4, but illustrating an eighthembodiment.

DETAILED DESCRIPTION

FIGS. 1-2 illustrate a pressure relief vent assembly 20 that mounts andseals to an opening 22 in vehicle structure 24. The assembly 20 includesa valve housing 26, which has a frame 28. The frame 28 includes fourvent openings 30 that allow for air flow from an interior portion (notshown) of a vehicle, such as a passenger compartment, to outside of thevehicle.

A set of flaps 32 includes a top flap 34, an upper middle flap 36, alower middle flap 38, and a bottom flap 40. Each flap in the set offlaps 32 has a periphery 42, which includes a hinge edge 44, an opposededge 46 that is opposite to the hinge edge 44, and a pair of side edges48 that extend between the hinge edge 44 and the opposed edge 46. Theperiphery 42 of each flap in the set of flaps 32 contacts with andgenerally seals around a respective one of the vent openings 30. Eachflap in the set of flaps 32 is secured-over a respective one of the ventopenings 30 in the frame 28—along its hinge edge 44. Each flap 34, 36,38, 40 and the portion of the frame 28 defining its corresponding ventopening form a valve 35, 37, 39, 41. While a vent assembly 20 with fourvalves is shown herein, of course other numbers of valves can be usedfor a particular vent assembly, as desired.

The top flap 34 includes a first hinge 50, the upper middle flap 36includes a second hinge 52, the lower middle flap 38 includes a thirdhinge 54, and the bottom flap 40 includes a fourth hinge 56. Each of thehinges 50, 52, 54, 56 extends adjacent and generally parallel to itsrespective hinge edge 44. Each hinge 50, 52, 54, 56, is bendable toallow its corresponding flap 34, 36, 38, 40 to pivot outward away fromthe corresponding opening 30 in one direction only—namely, in adirection that allows excess pressure in the passenger compartment to berelieved to atmosphere outside of the vehicle. When the pressures areessentially equal or the higher pressure acts in the opposite direction,the set of flaps 32 remain closed against the frame 28, greatly limitingor preventing air flow into the vehicle from the atmosphere. The hinges50, 52, 54, 56 are preferably living hinges (i.e., a thin or soft spotin the material that can repeatedly bend elastically and has a longfatigue life). Alternatively, the hinges may be a mechanical type ofhinge connecting each flap to the housing or connecting two portions ofeach flap together.

Each of the hinges 50, 52, 54, 56 has a varying width—that is, it iswider at a first end at one side edge 48 than at a second end at theopposite side edge 48, with a taper in between. This width variation ofthe hinges 50, 52, 54, 56 creates an asymmetrical closingcharacteristic, in this case an asymmetrical hinge spring rate. Theasymmetrical hinge spring rate means that the hinge spring rate is notconstant and uninterrupted from one side edge 48 to the other side edge48. That is, when the difference between the pressure in the vehiclerelative to atmospheric pressure outside of the vehicle is significant,the flaps will open to allow air to flow out of the passengercompartment. The asymmetrical hinge spring rate, though, will induce atwist in each flap 34, 36, 38, 40 as it opens. When the pressuredifference is reduced or eliminated, the flaps will return to theirclosed positions. As they return to their closed positions, the twistingeffect causes the periphery 42 of each flap 34, 36, 38, 40 to contactthe frame 28 sequentially rather than simultaneously. This sequentialcontact may reduce the peak noise generated during flap closing ascompared to conventional flaps. And, even though there is twistinginduced in the flaps 34, 36, 38, 40 while open, they all seal againstthe frame 28 when closed. The average width and amount of taper for thehinges 50, 52, 54, 56 can vary based upon the particular vehicleapplication.

FIG. 3 illustrates a second embodiment of a pressure relief ventassembly 120. The embodiment shown in FIG. 3 has many items in commonwith the first embodiment and to avoid unnecessary repetition of thedescription, the same reference numerals have been used but fallingwithin the 1 00-series. The significant difference with this embodimentresides in the fact that, not only do the hinges 150, 152, 154, 156taper, but they also vary from one flap 134, 136, 138, 140 to the next.That is, the first hinge 150 may have the same width as the hinges inthe first embodiment, while the second hinge 152 on average is slightlywider than the first hinge 150, the third hinge 154 on average isslightly wider than the second hinge 152, and the fourth hinge 156 onaverage is slightly wider than the third hinge 154. Thus, each hingewill have a hinge spring rate that is different from the other hinges.

Accordingly, each hinge 150, 152, 154, 156, and thus each valve 135,137, 139, 141, has a differing pressure inducing closingcharacteristic—they open and close at somewhat different pressuredifferentials. Consequently, in addition to each flap having its ownasymmetrical closing characteristic, the flaps 134, 136, 138, 140 havenon-uniform closing characteristics (differing pressure inducing closingcharacteristic) between them. This may further reduce the peak noiselevel as compared to the first embodiment in that not only do the flaps134, 136, 138, and 140 contact the frame 128 sequentially around theirperipheries 142 during closing, but the flap-to-flap variation willcause each flap, during closing, to contact the frame 128 at a slightlydifferent time than each of the other flaps. While the second embodimentshows this flap-to-flap variation, the other embodiments disclosedherein may also include a flap-to-flap variation as well.

FIG. 4 illustrates a third embodiment of a pressure relief vent assembly220. The embodiment shown in FIG. 4 has many items in common with thefirst embodiment and to avoid unnecessary repetition of the description,the same reference numerals have been used but falling within the200-series. The significant difference with this embodiment resides inthe fact that, the hinges 250, 252 (only first and second flaps shown)are now angled (non-parallel) relative to the hinge edge 244 of theflaps 234, 236. The angled hinges 250, 252 create the asymmetricalclosing characteristic for these valves 235, 237. The width of thehinges 250, 252 may be constant as shown in FIG. 4, or, if so desired,may include a taper similar to that shown in the first two embodimentsto increase the asymmetrical closing characteristic.

FIG. 5 illustrates a fourth embodiment of a pressure relief ventassembly 320. The embodiment shown in FIG. 5 has many items in commonwith the first embodiment and to avoid unnecessary repetition of thedescription, the same reference numerals have been used but fallingwithin the 300-series. The significant difference with this embodimentresides in the fact that the asymmetrical closing characteristic forthese valves 335, 337 is created by an angled opposed edge 346 ratherthan by asymmetry built into the hinges 350, 352. The opposed edge 346,and its corresponding opening 330 in the frame 328, are angled (i.e.,non-parallel) relative to the hinge edge 344 for each flap 334, 336(again only two flaps shown). As with the previous embodiments, theasymmetry in each flap 334, 336 causes a twisting during opening andclosing of the valves 335, 337, thus causing the periphery 342 of eachflap to contact the frame 328 sequentially rather than all at one time.Of course, one may, if so desired, provide asymmetry in the hinges aswell.

FIG. 6 illustrates a fifth embodiment of a pressure relief vent assembly420. The embodiment shown in FIG. 6 has many items in common with thefirst embodiment and to avoid unnecessary repetition of the description,the same reference numerals have been used but falling within the400-series. The significant difference with this embodiment resides inthe fact that the asymmetrical closing characteristic for these valves435, 437 is created by asymmetrical ribbing 460 protruding from orrecessed into the flaps 434, 436 (again only two shown) rather than byasymmetry built into the hinges 450, 452. The asymmetry caused by theribbing 460 causes the twisting leading to the periphery 442 of eachflap contacting the frame 428 sequentially. Of course, one may, if sodesired, provide asymmetry in the hinges as well.

FIG. 7 illustrates a sixth embodiment of a pressure relief vent assembly520. The embodiment shown in FIG. 7 has many items in common with thefirst embodiment and to avoid unnecessary repetition of the description,the same reference numerals have been used but falling within the500-series. The significant difference with this embodiment resides inthe fact that the asymmetrical closing characteristic for these valves535, 537 is created by asymmetrical step cutout features 562 in theflaps 534, 536 (only two shown) located between the hinges 550, 552 andtheir respective hinge edges 544. Again, the asymmetry induces thetwisting in the flaps 534, 536. Other types of asymmetry in the flapsdisclosed herein may be included in the flaps 534, 536 of thisembodiment as well, if so desired.

FIG. 8 illustrates a seventh embodiment of a pressure relief ventassembly 620. The embodiment shown in FIG. 8 has many items in commonwith the first embodiment and to avoid unnecessary repetition of thedescription, the same reference numerals have been used but fallingwithin the 600-series. The significant difference with this embodimentresides in the fact that the asymmetrical closing characteristic forthese valves 635, 637 is created by asymmetrical hinge step features 664in the flaps 634, 636 (only two shown). The hinge step features 664 arecreated by having one portion of the hinge closer to the hinge edge 644than another portion. Other types of asymmetry in the flaps disclosedherein may be included in the flaps 634, 636 of this embodiment as well,if so desired.

FIG. 9 illustrates an eighth embodiment of a pressure relief ventassembly 720. The embodiment shown in FIG. 9 has many items in commonwith the first embodiment and to avoid unnecessary repetition of thedescription, the same reference numerals have been used but fallingwithin the 700-series. The significant difference with this embodimentresides in the fact that the asymmetrical closing characteristic forthese valves 735, 737 (only two shown) is created by step jogs 766 inopposed edges 746 rather than by asymmetry built into the hinges 750,752. Each opposed edge 746, and its corresponding opening 730 in theframe 728, includes the step jog 766 so that one portion of the opposededge 746 is closer to the hinge edge 744 than another portion of theopposed edge 746. As with the previous embodiments, the asymmetry ineach flap 734, 736 induces a twisting during opening and closing of thevalves 735, 737, thus causing the periphery 742 of each flap to contactthe frame 728 sequentially rather than all at one time. Of course, onemay, if so desired, provide an asymmetry in the hinges 750, 752 as well.

Various alternatives to the embodiments disclosed above are alsocontemplated. For example, the third through eighth embodiments mayinclude variation between the respective flaps in a vent assembly tocreate a differing pressure inducing closing characteristic as discussedrelative to the second embodiment. In addition, the variation betweenthe respective flaps may include employing flaps from differentembodiments discussed above in the same vent assembly.

While certain embodiments of the present invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention as defined by the following claims.

What is claimed is:
 1. A valve for use in a pressure relief ventassembly for a vehicle, the valve comprising: a valve housing having aframe defining a vent opening; a flap having a periphery extendingaround and covering the vent opening, with the periphery including afirst side edge, a second side edge spaced from the first side edge, anda hinge edge extending from the first side edge to the second side edgeand affixed to the frame, the flap including a hinge adjacent to thehinge edge that is bendable when a pressure in the vehicle is greaterthan a pressure outside of the vehicle, and an asymmetric closingcharacteristic, wherein the asymmetric closing characteristic induces atwisting in the flap when the flap opens and closes; and wherein theasymmetric closing characteristic is defined by the hinge having awidth, the width of the hinge being in a direction generally parallel tothe first and second side edges, and the width tapering from a first endof the hinge adjacent to the first side edge to a second end of thehinge adjacent to the second side edge, and wherein the first side edgeis parallel to the second side edge along the entire width of the hinge.2. A pressure relief vent assembly for a vehicle comprising: a valvehousing having a frame defining a first vent opening and a second ventopening; a first flap having a first periphery extending around andcovering the first vent opening, with the first periphery including afirst side edge, a second side edge spaced from the first side edge, anda first hinge edge extending from the first side edge to the second sideedge and affixed to the frame, the first flap including a first hingeadjacent to the first hinge edge that is bendable when a pressuredifferential is greater than a first pressure difference between apressure in the vehicle and a pressure outside of the vehicle defining afirst pressure inducing closing characteristic, and wherein the firsthinge has a width, the width of the first hinge being in a directiongenerally parallel to the first and second side edges, and the widthtapering from a first end of the first hinge adjacent to the first sideedge to a second end of the first hinge adjacent to the second sideedge, and wherein the first side edge is parallel to the second sideedge along the entire width of the hinge; and a second flap having asecond periphery extending around and covering the second vent opening,with the second periphery including a second hinge edge affixed to theframe, the second flap including a second hinge adjacent to the secondhinge edge that is bendable when the pressure differential is greaterthan a second pressure difference between the pressure in the vehicleand the pressure outside of the vehicle defining a second pressureinducing closing characteristic, with the second pressure inducingclosing characteristic being different than the first pressure inducingclosing characteristic.
 3. The pressure relief vent assembly of claim 2wherein the second flap has an asymmetrical closing characteristic, andwherein the asymmetric closing characteristic induces a twisting in thesecond flap when the second flap opens and closes.
 4. The pressurerelief vent assembly of claim 2 wherein the second periphery includes athird side edge, a fourth side edge spaced from the third side edge, andthe second hinge edge, the second hinge edge extending from the firstside edge to the second side edge, and wherein the second hinge has awidth, the width of the second hinge being in a direction generallyparallel to the third and fourth side edges, and the width tapering froma first end of the second hinge adjacent to the third side edge to asecond end of the second hinge adjacent to the fourth side edge.
 5. Amethod for relieving a pressure from inside of a vehicle through apressure relief vent assembly, the method comprising the steps of:providing a valve, having a frame defining a vent opening covered by aflap having a periphery extending around and covering the vent opening,with the periphery including a first side edge, a second side edgespaced from the first side edge, and a hinge edge extending from thefirst side edge to the second side edge and affixed to the frame, theflap including a hinge adjacent to the hinge edge that is bendable whena pressure differential is greater than a pressure difference between apressure in the vehicle and a pressure outside of the vehicle, andwherein the hinge has a width, the width of the hinge being in adirection generally parallel to the first and second side edges, and thewidth tapering from a first end of the hinge adjacent to the first sideedge to a second end of the hinge adjacent to the second side edge andthe first side edge is parallel to the second side edge along the entirewidth of the hinge, to selectively allow for a flow of air from theinside of the vehicle to outside of the vehicle through the vent openingby flexing the hinge; bending the flap about the hinge to open the ventwhen the pressure inside the vehicle is greater than a pressure outsideof the vehicle by a predetermined amount of pressure; and inducing atwisting in the flap as the flap is bent about the hinge such that aperiphery of the flap will contact the frame around the vent openingsequentially upon closing.
 6. The method of claim 5 including the stepsof: providing a second valve, having a second vent opening defined bythe frame and covered by a second flap having a second hinge; bendingthe second flap about the second hinge to open the second vent when thepressure inside the vehicle is greater than the pressure outside of thevehicle by a second predetermined amount of pressure; and inducing atwisting in the second flap as the second flap is bent about the secondhinge such that a periphery of the second flap with contact the framearound the second vent opening sequentially upon closing.
 7. The methodof claim 6 wherein the first predetermined amount of pressure isdifferent from the second predetermined amount of pressure.
 8. Themethod of claim 6 wherein the step of inducing a twisting in the secondflap is further defined by providing the second hinge with anasymmetrical hinge spring rate.